The invention relates to a method and control unit for controlling an automatic transmission.
Automatic transmissions which are actuated automatically by way of an electronic control unit, in particular in order to engage a specific gearspeed, have already been known in motor vehicles for many years. In this context, the driver is provided with a selector lever by which at least one reverse gearspeed R, a neutral position N and a forward travel position D can be preselected manually. For some time, the Applicant has offered such automatic transmissions (BMW Steptronic) with an electronic selector lever. The invention is based thereon.
The object of the invention is to assist the driver even in extreme driving situations.
This and other objects are achieved according to the invention by a method for controlling an automatic transmission by way of an electronic control unit in a motor vehicle during a skidding turn, during which the motor vehicle firstly travels straight with a velocity above a predefined threshold value or within a predefined range with the reverse gearspeed engaged and, subsequently, experiences a defined steering jolt, by which a rotational movement is initiated. When a defined rotational angle is exceeded, the automatic transmission is automatically shifted from a reverse gearspeed into the neutral position.
The invention provides a method for controlling an automatic transmission by way of an electronic control unit in a motor vehicle during a skidding turn, during which the motor vehicle first travels straight with a velocity above a predefined threshold value (for example of 20 km/h) or within a predefined range (for example 20 km/h<v<40 km/h) with the reverse gearspeed engaged and, subsequently, experiences a defined steering jolt, by which a rotational movement (spinning) is initiated. When a defined rotational angle (for example 110°) is exceeded, the automatic transmission is automatically shifted from the reverse gearspeed into the neutral position.
In one development of the invention, when an end of the rotational movement is detected (for example, by use of the wheel rotational speed sensors after a maximum rotational angle of, for example, 180° has been reached), the automatic transmission is preferably automatically shifted from the neutral position into a forward travel position.
Other objects, advantages and novel features of the present invention will become apparent from the following detailed description of one or more preferred embodiments when considered in conjunction with the accompanying drawing.